This application is directed to a scanner or an interrogator for use in identification of objects, and more particularly, the identification of livestock temporarily detained by a livestock chute gate.
Difficulties have existed for some time with electronically reading identification tags mounted on livestock. First, the transponder to be monitored is typically passive, requiring more sensitive or powerful receiving capabilities by the interrogator than is needed with a battery powered transponder in order to detect and accurately receive an identification signal from the transponder. Second, regardless of whether the transponder is implanted or externally attached to the animal, the final position or orientation of the transponder cannot be controlled. However, for optimal performance, the transponder needs a magnetic field to be emitted along the length of the transponder antenna""s axis. Therefore, to optimize reading of a transponder, the axis of the transponder antenna must be aligned with the axis of the interrogator antenna. This is not always possible when dealing with live animals whose movement can cause the orientation of the transponder to change.
This problem has been addressed by assigning a worker to identify livestock. The worker given such a task, and given a hand-held reader or scanner, can adapt the position of the reader to effectuate a reading of the transponder attached to the animal regardless of the transponder""s position. For example, if a hand-held interrogator is used to read a transponder affixed to an animal""s ear, the worker is able to manipulate the reader by moving it and positioning it closer to, and at different angles relative to the animal""s ear in an effort to obtain a reading from the transponder. The same technique works for an implanted transponder. However, the cost in terms of wages and worker safety associated with dedicating a worker to the identification effort, due to necessarily working in close proximity to large animals, has provided motivation to attempt to automate the process. As a result, various types of automated identification devices have been developed.
U.S. Pat. No. 4,617,876 discloses an automatic scanner used to identify cattle while they are being fed and/or watered. However, it does not disclose a device for scanning livestock while the animal is located in a livestock chute, nor does it disclose a device that may be mounted on a livestock chute gate/door.
U.S. Pat. No. 6,000,361 discloses a method for optimizing cattle production in large feed lots using automated measuring, feeding, and calculation methods to determine cattle management requirements. However, it too fails to disclose a device for scanning an animal in a livestock chute, and it also fails to disclose a device that can be mounted on the gate or door of a livestock chute.
Finally, U.S. Pat. No. 5,686,902 discloses a generic system of tracking a number of identification tags; nonetheless, it fails to disclose a device that can be used to identify livestock within a chute.
Common problems associated with reading a transponder that is affixed to livestock include the fact that, many times, the animal is large and ponderous, with the ability to cause significant damage to a human in close proximity to the animal should reading the transponder using a hand-held reader be attempted. A further safety hazard exists if attempts are made to retrofit an existing livestock gate with a device that projects from the gate, thereby presenting an obstacle to workers when in a fixed position, or when the swing gate is activated and is in motion.
Another common problem is that livestock may be wet or covered with dirt and mud, or the chute may be near electrical motors or subject to adverse environmental conditions, such as rain or snow. Indeed, dirt, mud, manure and moisture on the equipment and/or on the animal can adversely affect the functioning of the electronics. Still yet another common difficulty is that it is necessary to construct livestock chutes to both guide and restrain large animals. Accordingly, this requires that the livestock chute be constructed of relatively strong, durable materials that can absorb the punishment of repetitive use and exposure to the impact of a multiple large animals repeatedly coming into contact with the chute structures. Such materials often incorporate ferromagnetic components, such as steel or other metals, that interfere with the radio frequency inductive coupling between the interrogator and the transponder. Therefore, any attempt to retrofit an existing livestock chute, or mount an interrogator to a new chute, must consider and sufficiently overcome interference presented by these ferromagnetic materials.
Ideally, a high inductance of approximately 700 microhenries is sought for an interrogator because a high inductance provides a better passive transponder read range. However, interrogators operating over about 400 microhenries have been found to be unstable in the setting of a livestock chute for multiple reasons. For example, and as mentioned above, detuning is a pervasive problem that is attributable to factors such as the mass of the animal near the antenna, mud, moisture or manure on the antenna and/or animal, moisture in the area of the antenna and movement of the antenna. These and other factors can detune the antenna, causing it to fail to read the animal""s transponder.
Another problem necessarily requiring attention is that positioning of an interrogator near an animal""s head results in the interrogator potentially being situated such that it is vulnerable to static loading from an animal resting its weight against the interrogator housing, and/or dynamic shock from the subject animal impacting the interrogator housing. Accordingly, these problems require that the interrogator be protectively positioned or otherwise located within a structural housing capable of maintaining its structural integrity in the face of such static and dynamic loading potentially caused by livestock.
It would therefore be greatly advantageous to address the above described problems and be able to remove a worker from the task of identifying livestock as the livestock travel through a passageway or chute, and yet still obtain accurate readings as to the identification of the animals moving through the chute. The present invention provides such a solution for both new and existing livestock chute structures.
It is an object of the present invention to provide an interrogator that can be mounted proximate the livestock chute and yet accurately read a transponder that is affixed to an animal within the chute. Accordingly, it is an aspect of the present invention to provide an improved interrogator antenna.
It is a further aspect of the present invention to provide an interrogator that operates at an inductance range to maintain a relatively stable flux field.
It is a further aspect of the present invention to provide an interrogator that can be directly affixed to the livestock chute gate.
Still another aspect of the present invention is to provide an interrogator that is less sensitive to the orientation of the transponder affixed to the subject animal whose identification is sought, and one that can accurately and reliably read a transponder regardless of its relative orientation.
Furthermore, it is yet another aspect of the present invention to provide a device that may be retrofitted to existing livestock chute structures and gates without affecting worker safety and while overcoming interference, tuning and ruggedness problems.
It is yet another aspect of the present invention to provide an interrogator whose structural housing serves as an integral component of the livestock chute or gate.
The above and other aspects of the invention are realized in specific illustrated embodiments of the invention. In general, the interrogator devices disclosed herein are preferably used in conjunction with a plurality of identification transponders. Each of the plurality of transponders is adapted to attach to an article to be identified. In use, an interrogator produces an interrogation signal for interrogating at least one of the plurality of transponders. In response to the interrogation signal, the transponders transmit an identification signal having an identification component, thus identifying the particular item to which the transponder is attached.
In a first embodiment, an interrogator device is provided that includes a transmitter having a first transmit coil wound in a first direction, a second transmit coil wound in a second direction different than the first direction, and a third transmit coil wound in a third direction different than the first or second directions. The first transmit coil, the second transmit coil and the third transmit coil are coupled to one another.
In a separate embodiment, an interrogator device is provided that includes a transmitter having a first transmit coil encompassed by a second transmit coil. The first transmit coil and the second transmit coil are electrically coupled to one another. The first transmit coil generates a first flux field, the second transmit coil generates a second flux field. The first flux field circumscribes the second flux field.
In a yet separate embodiment, an interrogator device is provided that includes an inner core having a longitudinal axis and a transmitter. The transmitter includes a first transmit coil wound around the longitudinal axis, a second transmit coil wound around the longitudinal axis, and a third transmit coil wound substantially parallel to the longitudinal axis. The first transmit coil, the second transmit coil and the third transmit coil coupled to one another.
In still yet a separate embodiment, an interrogator device is provided that includes a transmitter having a transmit coil, and a reflector shield situated proximate the interrogator device.
In yet a separate embodiment, an interrogator device and a mechanical gate combination are disclosed. The interrogator device includes a transmitter having a first transmit coil wound in a first direction, a second transmit coil wound in a second direction different than the first direction, and a third transmit coil wound in a third direction different than the first or the second directions. The first transmit coil, the second transmit coil and the third transmit coil are electrically coupled to one another. As noted, the combination includes an a mechanical gate, such as a cattle chute gate fitted with the interrogator device.
In yet a separate embodiment, a system for identifying characteristics of animals in a livestock chute is disclosed. The system includes a transponder mounted to an animal to be identified, an interrogator, and a reflector shield. The interrogator has an antenna assembly for transmitting an interrogation signal to the transponder, and for receiving an identification signal from the transponder. The reflector shield is situated proximate the interrogator, and projects a portion of the interrogation signal toward the transponder.
Finally, in yet a separate embodiment, a method of identifying an animal is disclosed. The method includes the steps of providing a livestock chute that can temporarily confine an animal, attaching a transponder to the animal, and attaching an interrogator proximate the livestock chute gate. The interrogator used in this method has a transmitter including a first transmit coil wound in a first direction, a second transmit coil wound in a second direction different than the first direction, and a third transmit coil wound in a third direction different than the first or the second directions. In addition, the first transmit coil, the second transmit coil and the third transmit coil are electrically coupled to one another. The interrogator also has a receiver. The method further includes the steps of providing a power source to the interrogator, transferring an animal to the livestock chute gate, generating an interrogation signal by activating the transmitter, receiving an identification signal from the transponder, processing the identification signal, and creating an output signal substantially corresponding to the identification component of the identification signal.
Still other aspects and advantages of the invention will in part be obvious and will in part be apparent from the specifications and drawings.